Lifting sling

ABSTRACT

A lifting belt sling for lifting loads is comprised of a tubular structure having at least two chambers whereby forming, as one unit, a chamber tube that is contiguous over the width. Loosely inserted inserts are located inside the at least two chambers and endlessly extend from one end of the chamber tube to the other end thereof. The inserts overlap the ends of the chamber tube so that they form loops at this location, whereby the inserts, when situated in the loop area, are covered by a tube protective means. A protective tube, which surrounds the chamber tube and is formed by different weaves, significantly increases the resistance to abrasion, the resistance to cutting, and the edge strength. The lifting belt sling is designed for loads of up to 100 t.

The invention relates to a lifting belt sling according to claim 1.

BACKGROUND

Round slings are predominantly used in industry, in the building tradeand in industry for lifting loads. Lifting belts are used in many waysin the transportation industry and especially in branches of building.

According to U.S. Pat. No. 4,210,089, a round sling is known whichincludes two chambers, in order thereby to obtain higher strength andimproved resistance to abrasion and cutting.

According to U.S. Pat. No. 5,238,278, a textile round sling is known,with additional ribs on the round sling tube, which thereby is to effectan improved cutting and abrasion resistance.

According to U.S. Pat. No. 5,651,572, a round sling is known whichincludes an additional strand of optical cables, in order to be able toemit a signal when there is a break.

According to U.S. Pat. No. 4,843,807, a method of production of roundslings is known, which relates to a rational production of a roundsling.

According to U.S. Pat. No. 5,498,047, a lifting belt is known whichconsists of a woven band, with loops and at least one reinforced edge,which is to protect against premature wear. An additional textile inlayis concerned as the reinforcement.

The following points are disadvantageous in round slings and liftingbelts:

Round slings are manufactured from a tube, which normally consists ofone chamber, but can also consist of two chambers as in U.S. Pat. No.4,210,089. Round slings are manufactured from endless yarn strands,which always give a round, endless ring or round tube, which can,however, be designed in their dimension such that they can lift loads ofup to 100 t. Since round slings give an endless ring, they cannot easilybe passed under a stationary load object.

Lifting belts are manufactured from woven belts, which according towidth and thickness can normally lift loads of up to 20 t. Lifting beltsare sewn together to form one piece with two-sided loops. This band canbe pulled through under a stationary load and suspended with the loopsinto a load hook on both sides. Since the bands are under strong stressdue to the load, they are very susceptible to wear and cuts. It isfrequently sought to eliminate this disadvantage with a costly coating.

SUMMARY

The present invention has as its object to propose a lifting belt withwhich the advantages of round slings are combined with the advantages oflifting belts.

A further object consists of substantially raising the service and uselife of the lifting belt loops over those of the conventional liftingbelts sewn of belt material and to design them for loads up to 100 t.

This object is attained according to the invention with a lifting beltsling according to the wording of claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in detail hereinafter using the drawings.

FIG. 1 shows a view of a lifting belt according to the invention.

FIG. 2 is a perspective sectional view of a lifting belt sling.

FIG. 3 is a perspective sectional view of a lifting belt sling withchambers of small width and large thickness.

FIG. 4 is a perspective sectional view of a lifting belt sling withchambers of large width and small thickness.

FIG. 4A shows a lifting belt sling with symmetrical inlays.

FIG. 4B shows a lifting belt sling with asymmetrical inlays.

FIG. 5 shows a chamber tube with coating applied to one side.

FIG. 6 shows a chamber tube with a surrounding protective tube.

FIG. 7 shows a lifting belt sling with two protective tubes.

FIG. 8 shows a first embodiment example of a lifting belt sling withloops of different length.

FIG. 9 shows a second embodiment example of a lifting belt sling withreinforced loop protection.

FIG. 10 shows a third embodiment example of a lifting belt sling witheyelets.

FIG. 11 shows a fourth embodiment example of a lifting belt sling withhooks and eyes.

FIG. 12 shows a fifth embodiment example of a lifting belt sling withwide/narrow woven chamber tube, protective tube and loop protection.

DETAILED DESCRIPTION

FIG. 1 shows a view of a lifting belt sling according to the invention.The lifting belt sling consists of a tube-like structure 20 which has atleast two chambers 2, 2′ and thus forms a chamber tube 1 which isbounded by ends 5, 5′. The chambers are formed in the production processand consist of synthetic yarns, woven fabrics, knitted fabrics, castplastic, extruded synthetic material, steel fabrics or chemicallyresistant material, leather or synthetic leather. In the at least twochambers are inlays which run endlessly from one side to the other side,or from one end 5 to the other end 5′, through the chamber tube 1.

The inlays 4 consist of single fibers or fiber bundles of high-strengthmaterials such as polyester (PES), polyamide (PA), polypropylene (PP),polyethylene (PE), Dyneema, Kevlar and steel strands. They are alsotermed tension inlays, since they take up substantially the whole load,while the chamber tube 1 surrounding them remains substantially unloadedunder tension and above all exerts a protective function. Asubstantially longer life thus results for the lifting belt sling. Theinlays and the protective tube can likewise consist of a combination ofthese materials, or of a mixed bundle of inlay fibers may be present.

The inlays 4 project beyond or overlap the ends 5, 5′ of the chambertube 1, so that loops 3, 3′ are formed there. The inlays are covered inthe loop region by a loop protection 6, 6′, which as a rule overlaps thechamber tube 1 and is connected thereto. It can, however, abut on theends 5, 5′ of the chamber tube 1 without being connected (not shown).The chamber tube can consist of, be covered with, or be coated withdifferent materials. Polyurethane, synthetic rubber, natural rubber,PVC, textile materials, bonded fibers, synthetic leather, leather, steelstrand fabrics, woven yarn fabrics, and knitted yarn fabrics areconcerned as materials. The inlays 4 introduced into the chamber tube 1and endlessly passed back through the chamber tube form a band withendless inlays with the loops 3, 3′ formed at both ends 5, 5′. The loopscan be covered with various protective materials, e.g. as fabric ortube.

FIG. 2 shows a perspective sectional view of a lifting belt sling. Thechamber tube 1 can be seen with its one end 5 and the chambers 2, 2′, ina line with which are four further chambers. The inlays 4 are located inthe chambers. The at least two chambers 2, 2′ are formed by sewing,knitting or weaving. Thus the chambers have, for example, seams lying inthe tension direction parallel to the inlays, whereby the chamber tubeis present, divided into chambers. Such lifting belt slings arepredominantly used for applications in the machine industry, in thebuilding trade, and for the transportation and goods industries, as isthe case of goods packaging locations of all kinds.

FIG. 3 shows a perspective sectional view of a lifting belt sling withchambers of small width and great thickness. The tension inlays 4 arearranged in the chambers 2, 2′ of the chamber tube 1, so that thechambers have a small width with a great thickness.

These belts are suitable above all for lifting large loads and areproduced for loads of up to 100 t with a safety factor of 7:1. Suchlifting belt slings find application in turbine building, for heavyloads in power plants, or in industry in general.

FIG. 4 shows a perspective sectional view of a lifting belt sling withchambers of large width and small thickness. The tension inlays 4 arearranged in the chambers 2, 2′ of the chamber tube 1 such that thechambers have a large width and a small thickness. Such lifting beltslings above all come into use when little space is available to pushthe lifting belt sling under the load. The chamber tube can thus have across section which is freely designed as regards thickness, width andinertia according to the use requirements.

FIG. 4A shows a lifting belt sling with symmetrical inlays. The inlays 4loosely inlaid into the chamber tube 1 are shown dashed here. The inlay4′ in the outer chamber of the one side of the chamber tube is conductedover the loop 3 and then conducted back as inlay 4″ into the outerchamber of the other side of the chamber tube. The inlays 4 and 4′ arethus located symmetrically with respect to a midline of the chambertube. All further inlays are likewise arranged symmetrically withrespect to this midline. This arrangement is termed “symmetric inlays.”

When the chamber tube now has very many adjacent chambers, it can “foldtogether” under a tensile force, i.e. it is deformed U-shaped.

FIG. 4B shows a lifting belt sling with asymmetrical inlays. The inlays4 loosely inlaid into the chamber tube 1 are shown dashed here. Theinlay 4′ in the outer chamber of the one side of the chamber tube isconducted over the loop 3 and then conducted back as inlay 4″ into aninner chamber of the other half of the chamber tube. The inlays 4 and 4′are thus located asymmetrically with respect to a midline of the chambertube. All further inlays are likewise arranged asymmetrically withrespect to this midline. This arrangement is termed “asymmetric inlays.”

When the chamber tube now has very many adjacent chambers, it can hardly“fold together” any more under a tensile force, since because of theasymmetrical arrangement a transverse component of the tensile forceopposes the deformation.

FIG. 5 shows a chamber tube with coating applied on one side. Thechamber tube 1 with the chambers 2, 2′ and inlays 4 is provided with acoating 7 on one side.

The chamber tube can have a coating applied on one side or two sides. Itcan, however, also be produced as consisting of a material which iswoven, knitted, extruded or cast, as an all-around coating. The coatingscan be cast, injection molded, calendered, powder coated, or applied bydoctor blade, and as a solution thereafter hardened. The chamber tubecan have a coating which consists of the same materials or as differentmaterials than the chamber tube.

FIG. 6 shows a chamber tube with a surrounding protective tube. Thechamber tube 1 is surrounded by a protective tube 8. Plural protectivetubes can be present, one over another. The protective tube can consistof natural or synthetic materials, of woven fabric, of knitted fabric,or as an extruded, cast element. The protective tube is arranged overthe whole length of the chamber tube or only a portion thereof, or itcan be made of several portions. The protective tube simultaneously actsas an abutment surface of the work goods and is therefore made ofdifferent materials according to the use requirements. According to theuse, it is especially flame resistant, flame retardant, or resistant toheat, chemicals, cutting and abrasion. It has a jacket of woven orknitted material or a double jacket, which in particular is resistant tochemicals and consists of polyamide (PA), polypropylene (PP), polyester(PES), or polyethylene (PE), or a mixed fabric of these materials. As arule it is manufactured of cut protection material which is highlyresistant to cutting, and by means of special kinds of weave has anextremely high edge strength, since the edges are not under tensilestress. Particularly heat-resistant and flame-retardant embodiments areof Kevlar, steel strands, Nomex or a combination thereof. Extremely highabrasion resistance, cut strength and edge strength are attained.

The chamber tube 1, the inlays 4, the coating 7, the protective tube 8and the edge protection can have the same or different materials.

The protective tube as well as the chamber tube can consist of extrudedor cast synthetic materials. PVC, PU, rubber or synthetic rubber, arubber mixture, natural or synthetic leather, woven or knitted steelstrands, woven yarn or knitted yarn fabrics, which are coated on oneside, both sides, or all around, are concerned.

According to the valid CE standards, the chamber tube, the protectivetube, the protective coating, the inlays and the edge protection canhave different materials.

CE Standard EN 1492-1 defines the lifting belt with prescriptions whichare fully adhered to by the arrangement and combination of the statedmaterials.

FIG. 7 shows a lifting belt sling with two protective tubes. The chambertube is present here, surrounded by a first protective tube 8, so thatit is covered from end 5 to end 5′. A second protective tube 8′ isinstalled over the middle portion of the first protective tube 8, sothat additional protection is guaranteed in this portion. The chambertube can thus be covered with plural like or different protective tubeswhich by means of their position or distribution permit a reinforcementprofile and a protection profile to exist over the whole length of thechamber tube, correct for the desired requirements.

A few embodiment examples are explained hereinafter.

FIG. 8 shows a first embodiment example of a lifting belt sling withloops of different lengths. The loops 3, 3′ are here made of differentlengths, so that they can be used optimally in respective applications.In this way, for example, the one loop of the lifting belt sling can belonger than the other for reasons of space with a differentaccessibility of the load. The lifting belt sling has a chamber tube 1of 4 m and loops of different lengths of 0.8 m and 1.8 m, which gives atotal length of 6.6 m. It is designed for a load of 100 t. The chambertube is divided into 14 chambers 2, 2′, in which inlays 4 of polyesterstrands are loosely inlaid. The chamber tube consists of polyesterfabric and is covered with a protective tube 8 of polyester fabriccoated with polyurethane which covers the whole chamber tube. The twoloops 3, 3′ have a loop protection 6, 6′ of polyamide fabric and wovenwide/narrow, the wide/narrow portion being located in the loopcurvature.

FIGS. 9-11 show loops 3, 3′ but do not show chamber tubes. It should beunderstood that a chamber tube is to be employed with the loops 3, 3′ inFIGS. 9-11, as shown in FIG. 1, and that the loops 3, 3′ are shownwithout a chamber tube merely for illustrative purposes.

FIG. 9 shows a second embodiment example of a lifting belt sling withreinforced loop protection. The loops 3, 3′ are provided next to theloop protection 6, 6′ with a reinforcement 9, 9′ in the region of thecurvature. This reinforcement consists of wide/narrow woven fabric, ofextruded or cast synthetic material. The loops 3, 3′ are as a rulesurrounded with a wide/narrow woven loop protection. The loop protection6, 6′ consists of a synthetic or natural material, of leather, ofsynthetic leather, of polyurethane, PVC, or bonded fiber.

FIG. 10 shows a third embodiment example of a lifting belt sling witheyelets. Eyelets 10, 10′ are here installed in the loops 3, 3′.

FIG. 11 shows a fourth embodiment example of a lifting belt sling withhooks and eyes, in which a hook 11 is installed in the one loop 3 and aneye 12 in the other loop 3′.

FIG. 12 shows a fifth embodiment example of a lifting belt sling with awide/narrow woven chamber tube, protective tube and loop protection. Thechamber tube is here surrounded by a protective tube which isnarrow-woven at the ends 5, 5′, as is the chamber tube, while it iswide-woven in the middle 13. The loop protection 6, 6′ is likewise wovenwide/narrow, and in fact narrow in the middle, so that it has a smallsurface and fits into the load hooks. The lifting belt sling can therebygive the load a wide support on the load abutment surface and have aspace-saving suspension in the loop region.

1. A lifting sling for lifting loads, wherein the lifting belt slingcomprises a tubular structure which has at least three chambersconnected adjacent to one another; wherein at least one inlay is locatedin the at least three chambers and runs endlessly from one end of the atleast three chambers to another end of the at least three chambers;wherein the at least one inlay stands out at the ends of the at leastthree chambers, so that loops are formed at the ends in a loop region;wherein the at least one inlay is covered by a loop protection in theloop region, and wherein the at least one inlay runs through each of theat least three chambers and is asymmetrically arranged, and wherein asingle loop is provided at each end of the at least three chambers.
 2. Alifting sling according to claim 1, wherein when the at least one inlayis under tension, the at least three chambers remain substantiallyunloaded.
 3. A lifting sling according to claim 1, wherein the at leastthree chambers are surrounded by at least one protective tube, whichextends over a portion thereof.
 4. A lifting sling according to claim 3,wherein the at least one protective tube comprises extruded or castsynthetic material comprising PVC, PU, synthetic rubber or a rubbermixture.
 5. A lifting sling according to claim 3, wherein the at leastone protective tube has a woven double jacket which is resistant tochemicals and comprises polyamide (PA), polypropylene (PP), polyester(PES), or polyethylene (PE), or a mixed fabric of these materials.
 6. Alifting sling according to claim 3, wherein the at least one protectivetube comprises cut protection material which is highly resistant tocutting.
 7. A lifting sling according to claim 3, wherein the at leastone protective tube is heat resistant and flame retardant and comprisesKevlar, steel strands, Nomex or a combination thereof.
 8. A liftingsling according to claim 3, wherein the at least one protective tube, bydifferent kinds of weaves, has an extremely high abrasion resistance,cut strength, and edge strength.
 9. A lifting sling according to claim3, wherein the at least three chambers, the at least one protectivetube, and the at least one inlay have the same materials.
 10. A liftingsling according to claim 1, wherein the at least three chambers comprisecast or extruded synthetic material.
 11. A lifting sling according toclaim 1, wherein the at least three chambers comprise polyurethane, PVC,synthetic rubber, natural rubber, leather, synthetic leather, bondedfiber materials, textiles, woven steel or knitted steel or wovenfabrics.
 12. A lifting sling according to claim 1, wherein the at leastthree chambers have a coating which comprises the same materials as theat least two chambers.
 13. A lifting sling according to claim 1, whereinthe at least three chambers are coated on one side.
 14. A lifting slingaccording to claim 1, wherein the at least three chambers are covered orcoated with polyurethane, PVC, synthetic rubber, natural rubber,leather, synthetic leather, bonded fiber materials, textiles, wovensteel or knitted steel or woven fabrics.
 15. A lifting sling accordingto claim 1, wherein the at least three chambers have a cross sectionwhose thickness, width and load limit are set according to userequirements
 16. A lifting sling according to claim 1, wherein the atleast three chambers are formed through sewing, knitting or weaving. 17.A lifting sling according to claim 1, wherein the at least threechambers have seams lying parallel to the at least one inlay in atension direction and by which a chamber tube is divided into chambers.18. A lifting sling according to claim 1, wherein the at least one inlaycomprises high strength materials comprising polyester (PES), polyamide(PA), polypropylene (PP), polyethylene (PE), Dyneema, Kevlar, mixturesof these, or of steel strands.
 19. A lifting sling according to claim 1,wherein the at least one inlay is present in the at least threechambers, the at least one inlay being arranged such that a large widthand a small thickness or a small width and a large thickness results.20. A lifting sling according to claim 1, wherein the at least one inlayis symmetrically arranged.
 21. A lifting sling according to claim 1,wherein the at least one inlay is loosely inlaid.
 22. A lifting slingaccording to claim 1, wherein the loops have the same length.
 23. Alifting sling according to claim 1, wherein the loops are covered byprotective material.
 24. A lifting sling according to claim 1, whereinthe loops have eyelets, hooks, or eyes.
 25. A lifting sling according toclaim 1, wherein the loops are surrounded by a woven loop protection.26. A lifting sling according to claim 1, wherein the loops are coveredwith a woven fabric or tube.
 27. A lifting sling according to claim 1,wherein the loop protection comprises a synthetic or natural material,of leather, of synthetic leather, of polyurethane, PVC, or bonded fiber.28. A lifting sling according to claim 1, wherein it is designed forloads of up to 100 tons.
 29. A lifting sling according to claim 1,wherein the at least three chambers are surrounded by at least oneprotective tube, which extends over the whole length of the at leastthree chambers.
 30. A lifting sling according to claim 1, wherein the atleast three chambers have a coating which comprises different materialsas the at least three chambers.
 31. A lifting sling according to claim1, wherein the at least three chambers are coated on two sides.
 32. Alifting sling according to claim 1, wherein the at least three chambersare coated all around.
 33. A lifting sling according to claim 1, whereinthe loops have a different length.
 34. A lifting sling according toclaim 1, wherein a single loop is provided at each end of the at leastthree chambers.
 35. A lifting sling according to claim 1, wherein eachchamber tube includes at least four chambers connected adjacent to oneanother; wherein at least one inlay is located in the at least fourchambers and runs endlessly from one end of the at least four chambersto another end of the at least four chambers; wherein the at least oneinlay stands out at the ends of the at least four chambers, so thatloops are formed at the ends in a loop region; wherein the at least oneinlay is covered by a loop protection in the loop region, and whereinthe at least one inlay runs through the at least four chambers.